The first shipment of shale gas produced by fracking is expected to arrive in Scotland in September.

One of a fleet of "Dragon-class" ships is due to arrive with the cargo at the Ineos petrochemical plant in Grangemouth.

Ineos says it has invested more than £1bn in the facility since it acquired the site in 2005.

The company has constructed the biggest shale gas storage tank in Scotland ahead of the arrival.

Fracking is the process of drilling down into the earth before a high-pressure water mixture is directed at the rock to release the gas inside.

It does not take place in Scotland due to a moratorium by the Scottish government.

'Significant investment'

The Grangemouth plant employs more than 1,300 people.

A statement on Ineos's website said: "In response to the 60% decline of North Sea gas over the last 10 years, we have no choice but to source our basic raw material (ethane) from outside the UK.

"Ethane from US shale gas will provide sufficient raw material to run our manufacturing site at full rates, something that has not been possible for many years.

"The successful delivery of the project is key to turning around the fortunes of the site and those companies and businesses that depend on our long-term presence in Grangemouth, together with the employees, customers and suppliers of those companies."

Ineos said the plant is "undergoing a radical transformation with significant investment that will herald a new era in petrochemical manufacture".

Cautious approach

It said: "Long-term contracts (15 years) have been agreed with suppliers to pipe ethane from the shale fields in the US to purpose-built export facilities on the east and Gulf coasts of America.

"From here, the gas will be shipped across the Atlantic in a fleet of eight specially-designed Dragon-class ships commissioned by Ineos.

"The project will return the Grangemouth site to profitability helping to secure its long-term operation, protecting the viability of its businesses and the many direct and indirect jobs that the site provides."

A Scottish government spokesman said: "The Scottish government is taking a cautious and evidence-led approach to unconventional oil and gas.

"Our moratorium ensures that no fracking can take place in Scotland.

"As previously reported, the Scottish government has commissioned a series of independent research projects to examine potential environmental, health and economic impacts to inform our evidence-led approach.

"This process is due to report later this year, with the public consultation taking place during winter 2016/17."